The automobile antenna widely used at present is the top rod antenna. But the rod antenna is long and will affect the aesthetics of the entire vehicle when being arranged at the top of the automobile. In addition, the common antennas usually have the defect of being vulnerable, and it is inconvenient for the automobile to be washed or enter a limited space when the antenna is too high. Besides, during usage, the antenna pole is easy to be dropped off, and the antenna shall be dismounted during the transportation, which is also inconvenient. Although there occurs a shark-fin shaped antenna of low height and aesthetic appearance (e.g., Chinese patent application CN1841843A), the mounting position of the antenna inside the case is limited, and the antenna is rather close to the automobile top, thus the radio signals are absorbed by the iron plate on the top of the automobile, and the receiving performance of the antenna is seriously deteriorated.